1. Field of the Invention
The present invention relates to a photographic film cassette, a method of manufacturing the same, and a package for the same. More particularly, the present invention relates to a photographic film cassette of which a leader of photographic film is exited outward from a cassette shell by rotation of a spool, and a manufacturing method and a package associated with the same.
2. Description of the Related Art
135 (35 mm) photographic film cassettes (hereinafter referred to as a cassette) are widely used. A conventional cassette has a metal cassette shell, which rotatably contains a plastic spool around which a photographic filmstrip (hereinafter referred to as film) is wound. The cassette shell is constituted of a cylinder made of a thin metal sheet and caps fitted on both ends of the cylinder. A leader of the photographic film protrudes from the cassette, even before the photographic film is used. To package this cassette, it is contained in a capfitted cylindrical plastic case called a P case, and overwrapped in a carton for retail sale. The P case is a moisture-proof inner packaging which protects the photographic film from moisture, and is transparent enough for visual detection of the cassette. The carton is used as an outer packaging for protection against ambient light and for printing indications such as the manufacturer's name and the type of the photographic film.
It is also known to utilize a photographic film cassette having a resinous cassette shell, instead of a metal cassette shell, as described in commonly assigned patent application Ser. No. 07/945,592. The cassette shell is constituted of two semi-cylindrical resinous shell halves. The photographic film is positioned so that the leader does not protrude from the cassette shell prior to loading the cassette in a camera. In such a cassette, when a spool is rotated to unwind the photographic film, the leader is caused to move through a passage mouth formed in the cassette shell and thereby exit from the cassette.
The carton described above is discarded after the P case, with the cassette therein, is removed from the carton for use. Although the carton is required for indication and protection, it requires excess materials and thus is wasteful and presents disposal problems. In order to eliminate the carton a P case must protect the cassette from ambient light and thus must be completely opaque, so that the cassette cannot be visually defected from the outside.
Cassettes, which have a resinous cassette shell and of which photographic film is positioned so that the leader does not protrude from the cassette shell prior to use require prevention of ambient light from entering a passage mouth in a more reliable manner than conventional cassettes. Accordingly, conventional cartons are inadequate for protection against ambient light in such resinous cassettes.